Question

My bloodhound/rot mix began having seizures when she was about 3 years altho we feel she may have been having them when we were not home, at work or something. She was put on phenobarbetol a few weeks ago but is having seizures about once a week and this is up from when the vet first diagnosed her. Why are vets so reluctant to prescribe liquid valium which I gather is an anticonvulsant that doctors use on dogs that are mid seizure. Hers are grand mall and stress her and me out so bad that I feel this could possibly a tool we could use to help her. Should I approach my vet about this? Most of the time we can tell when she is about to go into her seizure mode and if we gave her the anticonvulsant then, wouldn't it possibly stop it? Also she always seems to get a distinctive odor when she is about to have an episode. What is this caused from? Thanks for any advice you can give.